Spell: Hook Method

hook_method.rb

# ==================
# Spell: Hook Method
# ==================

# Override a method to intercept object model events.

$INHERITORS = []

class C
  def self.inherited(subclass)
    $INHERITORS << subclass
  end

end

class D < C
end

class E < C
end

class F < E
end

$INHERITORS # => [D, E, F]

# For more information: http://www.pragprog.com/titles/ppmetr/metaprogramming-ruby